[GAP Forum] Will my program ever finish?

[Gordon Royle]

I have four permutations, each of which has degree 76422528 (for those interested, this is the degree of a primitive representation of PSp(6,3)).

The permutations generate a group, which I believe to have order 9170703360 (this is twice the order of PSp(6,3)).

For various reasons, I wish to know how the extra factor of 2 is acting.


I can read the four permutations into GAP, and I can form the group generated by them, but now I need to compute with it.

I have just asked GAP for the order of the group, both for double-checking, and also so that it sets up the internal data structures needed for further computation.


But now it is sitting there, consuming cpu-time, but with no other indication of progress.

Initially it chewed up memory quite quickly for a while, but it has stabilised and seems to just be grinding on in the same memory footprint - I left it overnight, and the memory used has been constant.


Is there any way that I can guess whether this will finish (a) tonight, (b) tomorrow, or (c) just before the sun goes supernova?

Alternatively, can I “help” it by *telling* GAP the order of the group? (In Magma, I can _assign_ the order of the group and then use RandomSchreier to generate a bases/s.g.s). Of course, I lose the double-checking aspect of things, but I’m willing to do that if necessary.


Thanks

Gordon